Thats true but I'm prettys sure you must credit the creator in the way they specify. And avgvst hasn't specified anything.

But avgvst I plan on usng this whenever it rains im my game. The game is an iOS game, im calling it Particle Boy. I will put a link in my credits that looks like: "Mushrooms" by Avgvst. It will bring the player to the site, http://opengameart.org/users/avgvst

If this is okay with your or not let me know. Also if you want to change any of the names or URLS let me know.

And thanks for this awsome piece, it was honestly perfect for what I was looking for :D

I don't specify how I'd like people to credit me, because mechanically, there are several ways to go about it - whether you're using real names, handles, credit rolls, readmes or what-have-you.

Any way you want to do it is okay with me.

I don't license CC-BY to be restrictive, I do it because I feel CC0 absolves the artist of responsibility. It's good to have access to free art, but it's even better to have the support of an artist. Having my name attached establishes a line of communication.